This document provides further information about the methodologies we use, including:

key gap concepts and ideas

how we calculate the voluntary compliance ratio

the broad approaches we use to estimate each gap

the limitations of our approaches.

For each gap, we provide our methodology, data sources and key assumptions. The limitations specific to each gap and the reliability of the estimate are also provided.

The process of gap estimation is a technically complex task that, in essence, is the measurement of the unmeasurable. Our scope, methods, data and estimates will continue to evolve, and revisions and restatements to the estimates are likely to occur in future releases.

We are committed to publishing a comprehensive suite of gap measures covering the taxes and programs we administer. We will continue to add to our suite of gap estimates over time.

If you require further detail or wish to provide feedback, contact us at taxgap@ato.gov.au.

Our commitment to you

We are committed to providing you with accurate, consistent and clear information to help you understand your rights and entitlements and meet your obligations.

If you follow our information and it turns out to be incorrect, or it is misleading and you make a mistake as a result, we will take that into account when determining what action, if any, we should take.

Some of the information on this website applies to a specific financial year. This is clearly marked. Make sure you have the information for the right year before making decisions based on that information.

If you feel that our information does not fully cover your circumstances, or you are unsure how it applies to you, contact us or seek professional advice.